The present invention relates generally to a test fixture for measuring selected electrical parameters of a test substance, and more particularly pertains to a test fixture designed to aid in the accurate measurement of the quality factor (Q), dissipation factor (D) and dielectric constant (K.sub.s) of a wax which is utilized as a dielectric in telephone transmission cables. A cable wax having a low D and high K.sub.s will minimize cross talk between adjacent wires in a transmission cable. The designed use of the present invention is the verification of these measured electrical parameters after manufacture of the wax.